The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Hybrid powertrains typically include a first torque generator, such as an internal combustion engine (ICE), and a second torque generator, such as an electric machine (EM). Both can provide torque to a driveline to propel a vehicle.
In a full hybrid powertrain, the EM can drive the drivetrain directly, without transferring torque through a component of the ICE. In a mild hybrid powertrain, the EM is coupled with the ICE, through the accessory drive. Torque generated by the EM is transferred to the drivetrain through the ICE. An exemplary mild hybrid powertrain includes a belt alternator starter (BAS) system. In the BAS system, the EM is coupled to the ICE via a traditional belt and pulley configuration, which drives other accessory components including, but not limited to, pumps and compressors.
Because the EM adds weight and cost to the vehicle, the efficiency of the EM needs to be optimized.